Daniel Rudman

Lipemia-Producing Activity of Pituitary Gland Separation of Lipemia-Producing Component from Other Pituitary Hormones

Summary A method for fractionation of hog pituitary glands by saline extraction, fractional precipitation with acetone at pH 4.3, and ion-exchange chromatography, is described. The final fraction has high lipemia-producing activity in the rabbit and is free of recognized pituitary hormones. Lipemia-producing activity of this fraction is enhanced by simultaneous injection of ACTH. Production of lipemia in the rabbit by injection of ACTH together with commercial preparations of TSH, prolactin or FSH is also described. In the combination ACTH + commercial TSH, evidence is presented that ACTH acts in synergism with some “contaminating” substance in commercial TSH preparation, rather than with TSH itself.

Lipemia in the Rabbit Following Injection of Pituitary Extract.

Summary An extract prepared from lyophilized hog anterior pituitary gland produces lipemia in rabbits. A similar effect is produced by whole pituitary glands from men, hogs, sheep, and cattle. Activity of the crude extract of lyophilized glands is considerably greater than can be accounted for by the presence of any of the purified anterior pituitary fractions so far tested. This suggests that the lipemia-producing substance is distinct from the recognized pituitary hormones, or that 2 or more pituitary hormones act in a synergistic manner upon the rabbits serum lipids.

Evolutionary Changes in Adipose Tissue Physiology

It is now about 10 years since the intensive investigation of adipose tissue began. Until the 1930’s, this tissue was considered a metabolically inert depot of excess calories stored as triglyceride. During the next 3 decades, a series of key observations gradually kindled interest in the possibility of a more dynamic role of the adipose organ in the body’s metabolism: The capacity of pituitary extracts to cause an acute mobilization of adipose tissue lipid (Best and Campbell, 1936); demonstration of the rapid turnover of adipose lipid by Schoenheimer and Rittenberg (1936); the avid uptake of glucose, and incorporation of the hexose carbons into stored lipid, by adipose tissue slices incubated in vitro (Shapiro and Wertheimer, 1948;Hausberger et al, 1954); discovery in 1956 of the circulating free fatty acids (FFA), recognition that this plasma lipid is secreted into the blood by the fat cells, and demonstration that its plasma concentration fluctuates continuously in rapid response to changes in carbohydrate intake and utilization (Gordon and Cherkes, 1956; Dole, 1956; Laurell, 1956).